AY.4.2, A Delta Covid-19 Coronavirus Subvariant, Has Spread To 42 Countries – Forbes

Ay, yet another version of the Covid-19 coronavirus.

There are variants of the Covid-19 coronavirus like the Delta variant. Then there are subvariants, which are variants of the variants. And AY.4.2 is a Delta subvariant that has now spread to at least 42 different countries, including the U.S., according to the latest World Health Organization (WHO) Weekly epidemiological update on Covid-19. This AY.4.2 takes the Delta variant and raises it three additional mutations, including two that affect the oh-so-important spike proteins that studs the surface of the virus. These mutations are called A222V and Y145H, which sound like relatively weak passwords for your XXX accounts. Some have called this subvariant “Delta plus,” although it isn’t necessarily the only “Delta plus” out there, as I covered previously for Forbes.

The big question, of course, is whether these mutations make the virus more transmissible. And more harmful such as more deadly. OK, the two big questions are whether these mutations make the virus more transmissible and harmful. And more able to dodge immunity from the vaccine or previous infection. OK, there are three big questions.

It shouldn’t be that much a surprise that new variants and subvariants keep emerging. After all, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a horny bleep. This isn’t a reference to the spike proteins that make the virus look like one of the a spiky balls used in BDSM, not that you would necessarily know anything about that. No, it refers to the viruses’ interests in reproducing a lot. Once the viruses gets into your cells, they have one clear agenda, to make many, many more copies of themselves. They are like that person who arrives at a first date and says as an opener, “OK, when are we going to have sex?”

Each time the virus replicates, it can be like a drunk person making photocopies of his or her butt. The virus can make mistakes so that the subsequent copies of the virus may be slightly off with mutations sprinkled in their genetic code. Some of these mutations may make the resulting new versions of the virus weaker. Others may make no difference. And some can make the virus stronger, which are the mutations that public health officials are worried about as this bleeping pandemic continues.

A new version is a subvariant rather than a totally new variant if it is clearly a variation of an original existing variant. Got it? In other words, is the new version something completely different? If so, then it is a new variant. If it clearly arose from additional mutations to an existing variant, then it can be considered a subvariant. The Delta variant has already had a lot of “offspring” so to speak: 67 different lineages according to the WHO report. A lineage is a family line. Each family line itself can continue to generate further variations.


To understand the concept of lineages, think of viruses as you would people. Viruses like people can beget offspring, although not many people will have hundreds or even thousands of kids. It would be difficult to pack so many kids into an SUV. Plus, it takes much longer for a given person to generate offspring. First you have to get on a dating app, then you have to select a restaurant and so forth. Genealogists can re-create a family tree, which will include combinations of different family lines or lineages by using genetic information. They may compare the genetic sequences of various people to see who may have been their parents and how everyone may connect with each other. Similarly, throughout the pandemic, a network of scientists across the world have been submitting genetic information from virus samples to global data repositories.

This has helped divide the Delta variant family tree into three clades: 21A, 21I, 21J. Dictonary.com defines a clade as “a group of organisms considered as having evolved from a common ancestor.” So in theory you could tell your parents, “yo, give it up for our clade.”

While reports of AY.4.2 have been going up since July of this year, the subvariant still only accounted for about 5.9% of all reported Delta cases reported in the week of October 3. So, it’s not as if AY.4.2 has sweeping the world just yet. Nevertheless, the AY.4.2 subvariant has been increasing at a modest rate in the United Kingdom (U.K.), which has provided 93% of the AY.4.2 reports to date. Eric Topol, MD, founder and director of the Scripps Research Translational Institute, referenced an October 29 briefing from the U.K. Health Security Agency in the following tweet:

The briefing reported that “the Delta sublineage AY.4.2 (VUI-21OCT-01) accounts for a slowly increasing proportion of cases in the UK. It accounts for 8.5% of Delta cases in the most recent complete week of sequencing (4 October 2021 to 10 October 2021). In more recent weeks, sequencing data are incomplete, however AY.4.2 accounts for 10.3% of Delta cases in the week 11 October 2021 to 17 October 2021 and 11.3% in the week 18 October 2021 to 24 October 2021.” So an increasing percentage of Delta cases are in fact the AY.4.2 subvariant. This suggests that the AY.4.2 may be more transmissible and thus spread more readily than the original Delta variant.

According to the briefing, there is further evidence that the AY.4.2 subvariant may be a bit more transmissible than the original Delta variant. For example, people infected with the AY.4.2 subvariant have ended up infecting on average a higher percentage (12.4%) of their household members than those infected with the original Delta variant (11.1%).

That ain’t great news. However, take a look at the tweet thread from Meaghan Kill, an epidemiologist at the U.K. Health Security Agency, on what they’ve found regarding vaccine effectiveness against the AY.4.2 subvariant. She began the October 29 thread with “Happy Friday,” which is not how you usually start off bad news threads. Typically, you don’t say something like “Happy Friday! Your eyeballs are about to fall out of your head.” Here’s how Kill’s thread began:

Well, that second tweet certainly didn’t kill the “Happy Friday” vibe. “No evidence that VE (infection) is lower for AY.4.2” is good news. Her tweet thread continued with the following:

OK, there could be a slight reduction in VE against symptomatic infection for the Pfizer/BioNTech Covid-19 vaccine. But “negligible impact” is not a huge deal. The large smiley face in her last tweet seems to be vibrating with some happiness rather than trembling with terror. The bottom line is that it looks like the currently available Covid-19 vaccines remain quite effective against the AY.4.2 subvariant, which is good news. Of course, public health officials and scientists should continue to monitor the situation and study the subvariant.

Regardless, the spread of this AY.4.2 subvariant, this “Delta plus,” is a reminder that the Covid-19 coronavirus can keep evolving. That’s why getting as many people vaccinated as soon as possible is so important. Reaching herd immunity thresholds can break the chain of virus transmission and thus slow the emergence of new variants. It can also better protect the population against future variants so that the SARS-CoV-2 becomes more like other seasonal respiratory viruses such as the flu. The influenza virus became less deadly over time as more and more people were repeatedly exposed to the virus through a combination of vaccinated and natural expose.

This can happen as soon as 2022 for the Covid-19 coronavirus. As long as enough people in countries around the world get fully vaccinated, this pandemic can turn into something that’s more endemic. And ay, people everywhere sure are ready to see the “end” attached to this pandemic.